Those are some of the applications being tried or considered for millions of old tires being shredded by Rumpke Recycling with a new, more powerful tire shredder recently installed at the Brown County Landfill outside Georgetown.

The project, among a handful funded this year in the first round of grants by the Ohio Department of Natural Resources' scrap tire market development program, is part of a new effort by the state to deal with unwanted old tires banned from the state landfills since 1988.

"What we hope to do is develop long-standing markets for scrap tire materials,'' said Chet Chaney, market development director for the ODNR program.

The Ohio Environmental Protection Agency estimates that 22.8 million old tires are now in the state's licensed landfills. Beyond that, Ohioans throw out another 12 million to 14 million tires annually when they replace worn-out rubber on their cars and trucks.

A cap of ground tires forms part of the base over the Brown County Landfill.
(Glenn Hartong photo)
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Tire dumps are a fire and health risk. Standing water in old tires offers a breeding grounds for mosquitoes, which can carry West Nile virus and other illnesses." We have to worry about the ongoing problem of where these tires are going to go each year, beyond the issue of cleaning up existing tire dumps,'' Mr. Chaney said.

ODNR, which took over the scrap tire market development effort more than a year ago from the Ohio Department of Development, has about $1 million to commit annually to projects funded through a portion of the $1 fee the state collects on tire disposal. Most of the fee is used to fund tire dump cleanup. "Our job is to develop markets so we have processors out there collecting tires, processing them into a commodity which can then be sold into a market,'' Mr. Chaney said.

Rumpke matched the $295,854 state grant with money of its own to buy the new Columbus McKinnon Corp. equipment, which can shred up to 1,500 tires an hour.

More than 300 knives in the diesel-powered machine reduces full-sized tires - steel belts and all - to roughly 2-inch chips in a matter of seconds, said Ken Stidham, Rumpke's operations manager for recycling.

The company has two other older shredders - one at an Indiana landfill and another at D&R Recycling, a Hamilton tire processor. But those machines produce larger shreds, unsuitable for the new markets Rumpke wants to tap: civil engineering applications such as landfill liners and road beds and as a coal-fired boiler fuel known as TDF, or tire-derived fuel.

Since receiving the new shredder earlier this fall, Rumpke has ripped about 1.2 million old tires to produce a 3-foot thick landfill liner for half of a 10-acre area at the Brown County landfill.

The other 5 acres were covered with more expensive sand, Mr. Stidham said. The new 10-acre site will extend the landfill's life for about three years.

Michael Blumenthal, senior technical director for the Rubber Manufacturers Association, said civil engineering uses and tire-derived fuel are the two fastest growing applications for scrap tires.

Last year, 115 million tires were burned as TDF, Mr. Blumenthal said. That's up from just 25 million in 1990 and "we expect that number to increase,'' he said.

Civil engineering applications have been a more recent development but are growing even faster.

"Before 1997, less than 5 million tires a year were going into civil engineering applications, but last year, that number had increased to 40 million,'' he said. "It's growing at a faster rate than any other major market.''

Outdoes coal for heat

Old tires as boiler fuel have a number of advantages. They produce more heat per pound than coal - 15,000 British Thermal Units versus 12,500 BTUs for coal, he said.

In addition, tires contain virtually no nitrogen, unlike coal, so burning them as a supplement to coal reduces nitrogen oxide emissions, an ingredient that can trigger ozone pollution or smog.

Mr. Blumenthal cautions that scrap tires will never replace coal as a fuel source, but they can help utilities and other industrial plants reduce the pollution and cost of burning coal.

"I describe the relationship of tires to coal as tires being a fly on the rump of the (coal) elephant,'' he said.

Today, about 70 industrial plants across the United States burn scrap tires as boiler fuel, Mr. Blumenthal says, mainly pulp and paper mills, cement kilns and utility power plants.

"It's been catching on in the cement industry and is pretty much standard operating procedure now,'' he said.

No Ohio plant burns scrap tires for fuel on a regular basis, but that might soon change.

One of the initial ODNR grants was to install a scrap-tire feed system for steam boilers in Akron.

And Cinergy Corp. also received a $35,000 state grant to process 60,000 scrap tires as a test at the utility's Miami Fort power plant in North Bend.

A Cinergy spokesman said the utility hasn't finalized plans for the test yet and probably won't until next year when construction is completed on new pollution control equipment at the power plant.

More imminent is a test planned in January by Carmeuse Lime & Stone Inc., formerly Dravo Lime Inc., in Maysville, Ky.

The Maysville plant makes calcium oxide by heating Kentucky limestone in four large kilns. Utilities such as Cinergy use the calcium oxide to remove sulfur dioxide, a pollutant, from their power plants.

Carmeuse now uses coal to heat the limestone but will test TDF supplied by Rumpke early next year, said George Love, regional environmental manager for Carmeuse.

If successful, the plant envisions consuming up to 1.5 million tires a year.

"The tires will produce more heat for less money,'' he said. "There are some real economic incentives to do this.''

The plant tested tires once before in 1998 but wasn't able to measure gas emissions. This time around, it wants to be able to document any emissions to alleviate concerns about the tires adding to pollution, Mr. Love said.

Concerns over emissions

Environmental groups such as the Sierra Club have opposed burning tire shreds because of concerns over toxic emissions. "It's a bad idea,'' said Glen Brand, Midwest regional representative of the Sierra Club.

Concerns are that burning tires will increase emissions of metals such as zinc, chromium and cancer-linked dioxins and furans. "Coal plants aren't set up to capture those emissions,'' Mr. Brand said.

Mr. Blumenthal said environmental groups are opposed to all types of combustion as a source of pollution. Overcoming negative perceptions about burning tires as fuel is one of the biggest hurdles the process faces, he said.

The heavy black smoke and ash from uncontrolled tire fires, like the one at the Kirby landfill outside Toledo a couple of years ago, leave the impression that all tire burning is bad, Mr. Blumenthal said.

But those kind of uncontrolled burns at low temperatures in the open air are nothing like burning tires at high temperatures in a controlled environment like a boiler, he said.

"It works. It's cleaner than coal, costs less and has the ability to produce a net reduction in your emissions,'' he said .

Mr. Chaney at the ODNR said the state wants to foster a variety of markets for scrap tires.

"One message we've heard, to be successful, you need to focus on a number of markets or applications,'' he said.

"If you focus on one project, or market, you don't tend to be as successful as a diversified program.''